This application relates to central vacuum cleaning systems, and particularly an adaptor for use in an inlet valve assembly employed in such systems.
Conventional inlet valve assemblies consist of an inlet valve having a cover plate disposed primarily on the outer surface of a wall, and a mounting bracket assembly, usually of metal, and disposed on the inner surface of a wall, such as a conventional stud and drywall structure commonly used in residential buildings. The inlet valve includes a decorative cover or face plate which lies against the outer surface of the wall, similar to the cover plate which overlies a conventional light switch or duplex outlet. However, in the case of the central vacuum inlet valve face plate, the plate has a circular aperture therethrough and a cylindrical extension extending from the back of the aperture through the wall and adapted to communicate with tubular ducting which leads to the central vacuum power unit. The face plate is provided with a spring biased flap which lies flush with the surface of the face plate to cover the circular opening when the inlet valve is not in use, but which may be drawn away from the surface of the face plate against the bias of the spring to permit insertion of one end of a hose and nozzle assembly. The inlet valve includes, within the cylindrical extension, two electrical contacts which coact with the inserted end of the hose and nozzle assembly to automatically initiate operation of the central vacuum power unit upon insertion.
The mounting bracket assembly is essentially a flat metal plate which is disposed behind the wall and is normally secured to a wall stud or the like. The bracket plate is provided with a relatively large inlet aperture which receives the cylindrical extension on the rear of the face plate, and additional apertures to receive fasteners required to secure the bracket plate to a wall stud or the like, to secure the inlet valve face plate to the mounting bracket plate, and to permit the passage of electrical wires therethrough for connection into the back of the face plate and to the aforementioned electrical contacts therein. The mounting bracket assembly is further provided with a deformable gasket about the inlet aperture to snugly and sealingly receive the cylindrical member of the face plate, the gasket being interposed between the mounting bracket plate and the end flange of a cylindrical connecting member adapted to be connected into the tubular ducting. The flange of the cylindrical member, the sealing gasket, and the mounting bracket plate are secured together by means of rivets or like securement means, and together form the inlet valve mounting bracket assembly.
When a central vacuum system is being installed in a new residence, the inlet valve mounting bracket assembly is installed in a desired location, for example, by securing the mounting bracket assembly to one of the studs before the drywall is applied, and the tubular ducting is installed between the mounting bracket assembly and the central vacuum power unit, with the cylindrical connector of the mounting bracket assembly being glued or otherwise secured into an end of the tubular ducting. Electrical wires are then passed through one of the electrical apertures in the mounting bracket plate, and the drywall is applied to the studs with an opening being provided adjacent the mounting bracket assembly inlet aperture. As a final step in completing the wall and the central vacuum system, the inlet valve is applied to the outer surface of the wall, with the electrical wires first being connected to the contact connectors on the back of the face plate, and the cylindrical extension on the back of the face plate being inserted through the inlet aperture of the mounting bracket assembly, and snugly retained therein by means of the circular gasket to provide a sealed communication between the cylindrical extension and the ducting leading to the central vacuum power unit. The face plate is then secured to the mounting bracket assembly by insertion of screws or like fastening devices through apertures in the face plate and into the fastening apertures on the mounting bracket in a manner similar to the cover of a conventional light switch or duplex outlet.
The inlet valve is relatively easy to install in a system such as that just described. However, the mounting bracket assembly is relatively expensive to produce, in that it comprises a number of parts, i.e., the relatively flat mounting plate, the circular gasket about the inlet aperture, the flanged cylindrical connector, and the connecting means (usually four rivets or screws are employed) for connecting the flange, gasket and the mounting plate together. Further, the apertures through which the electrical wires pass are normally punched out of the flat plate, with the result that their edges are relatively sharp and can readily damage the insulating covering on the wires. Any attempt to remove the sharp edges would result in considerable additional processing or hand labour, and would increase the complexity and cost of production of the mounting bracket assembly.